MEMPHIS — No single individual is responsible for a backlog of 12,000 rape kits that sat untested for years in Memphis, a report said.

A report compiled by former U.S. attorney Veronica Coleman-Davis says no one maliciously or wantonly allowed thousands of sexual assault kits to remain untested since the 1980s.

Instead, the report attributed the problem "to a general and collective failure to understand the importance of DNA testing as was reflected in common practices in place locally and nationwide."

Word of the backlog emerged last year, and it has led to a lawsuit from rape victims.

Memphis has one of the nation's largest known backlogs, experts say. Thousands of the backlogged kits have since been tested, and authorities are working to identify suspects from the evidence and charge them, officials say.

There are efforts to raise the estimated $5 million to $6 million needed to fund the entire process, with $2 million already secured, the report released Tuesday said.

"The caseloads are already high, and burn out is and will be a challenge in addressing the untested kits," the report said. "Funding will be needed to increase staffing."

The Joyful Heart Foundation, a national organization with experience in dealing with rape kit backlogs, has been enlisted to help in the testing process.

Memphis Mayor A C Wharton Jr. thanked Coleman-Davis in a statement.

"Her neutral approach and independent findings give me confidence that our plan to get all untested kits tested is on target and that we will be successful in our efforts to seek justice for the survivors," Wharton said.